Access to quality healthcare is a challenge for minority and disadvantaged groups in the U.S. Systemic lupus erythematosus (lupus), a complex autoimmune disease, can cause nephritis and, in severe cases, end-stage renal disease. Lupus nephritis is a potentially preventable outcome that disproportionately afflicts vulnerable groups: women, racial and ethnic minorities, the poor, those lacking medical insurance and education, and children and the elderly. We have found that the incidence of lupus end- stage renal disease rose dramatically from 1995-2004 in the U.S., in particular among those 20-39 years old, women, and racial and ethnic minorities. More new cases now occur among Blacks than whites. The causes of these growing disparities are unknown. We hypothesize that multiple barriers to quality healthcare for lupus nephritis exist for disadvantaged patients and are responsible for premature, excess, and avoidable morbidity and mortality. Our goals are to identify and prioritize potentially remediable barriers to healthcare access for lupus nephritis and end-stage renal disease, leading to both future research and policy interventions. Our uniquely qualified interdisciplinary research team will address nationwide socio-demographic variation in lupus nephritis healthcare and the potentially modifiable factors responsible for outcome disparities. We will constitute two nationwide cohorts: one with > 5000 patients with incident lupus nephritis from 2000-2004, and a second with >14,000 patients with incident lupus end-stage renal disease from 1995-2009 and investigate the factors that contribute to access to care and disparities. We have developed a conceptual model for understanding the determinants of health disparities in lupus nephritis and posit that potentially modifiable factors, such as subspecialist care, provider and medical center volume, medical insurance, and adherence to therapy, contribute to long-term outcomes in lupus nephritis, including the development of end-stage renal disease and death. Lupus patients from the affected communities will likely have great insight into our findings and should be involved in the development of strategies for overcoming observed barriers. We will perform focus groups of community lupus patients and investigate the barriers to quality healthcare for lupus nephritis and end-stage renal disease from patients' perspectives. The multidisciplinary research team will be composed of investigators with expertise in healthcare disparities research, biostatistics, pharmaco-epidemiology, administrative claims data, lupus epidemiology and quantitative research methodologies. The findings will be widely disseminated to the lupus community, physicians and healthcare workers. The results will provide guidance to clinicians and policy makers on strategies to reduce barriers and improve access to care and outcomes for all Americans with lupus nephritis.